In the 19th century, Alvan Graham Clark was one of the premier lens makers for telescopes. His craftsmanship was sought after and many observatories in the late 19th and early 20th centuries were built to house his refractor telescopes. In fact, smaller Alvan Clark refractors are also sought after by amateur astronomers when they are on the used market.
You have an opportunity to look through a Clark Telescope at the Dearborn Observatory, located at Northwestern (Evanston, IL). The observatory has public viewing on Fridays, weather permitting. And, if you are interested in learning about the history of Alvan Clark refractors, come visit our March fundamentals talk, presented by NAA member Ed Armstrong.
May ’25 — Rick’s Picks
Transient Events That Can Give Us a Good Enough Reason to Get Outside and Do a Little Observing All month: the planets continue their exodus from the evening sky this month. Uranus is now lost in the solar glare – it will reach conjunction on May 17 and return as a...
The Cosmologist’s Puzzle: The Age and Expansion Rate of the Universe.
We are confused about how old the Universe is. Until recently, astronomers estimated that the Big Bang occurred between 12 and 14 billion years ago. Astronomers can place a lower limit to the age of the universe by studying globular clusters. Globular clusters are a...
April ’25 – Rick’s Picks
Transient Events That Can Give Us a Good Enough Reason to Get Outside and Do a Little ObservingAll month: the solar system balances morning and evening targets this month as Mercury, Venus, Saturn, and Neptune move into the predawn sky, while Mars, Jupiter, and Uranus...
Astronomy Fundamentals: What We Can Learn from Impact Craters
Impact craters can be found throughout the solar system. NASA scientists use impact craters and volcanic activity to learn about the process throughout the solar system. By studying craters on Earth, scientists gain knowledge of volcanic landform formation and...